enVision Mathematics Grade 2, Topic 1: Fluently Add and Subtract Within 20
In this unit, the year opens with addition and subtraction facts within 20. Your child uses strategies like doubles, making ten, and counting on, and learns how addition and subtraction facts are related. They also solve story problems with those facts. Quick, sure facts help with the work on equal groups that comes next, and with every larger problem later in the year.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Topic 1?
- Solving story problems within 20 by deciding whether to add or subtract and writing an equation with a box for the unknown. Learn more: One- and two-step story problems within 100
- Building fluency with facts within 20, using doubles, near doubles, making ten, and related facts in a fact family. Learn more about adding fluently within 20: Adding fluently within 20 · Learn more about subtracting fluently within 20
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
What is 80 minus 20?
- 50
- 60
- 70
How you can help
- Play "Make Ten" with a deck of cards: find pairs that add to 10, then use them to solve facts like 8 + 5 by thinking 8 + 2 + 3.
- Turn snack time into a story: "You had 14 crackers and ate some. Now there are 6. How many did you eat?" Ask for the matching addition fact.
- Call out a double on a walk or ride, like 7 + 7, then a near double, 7 + 8, and ask how the first fact helps with the second.
Where kids can get stuck
- Working out 14 − 8 from scratch instead of asking what adds to 8 to make 14.
- Adding every time a story says "more," even when the story asks how many more one person has.
- Counting by ones for every fact, which is slow and leads to small slips.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- doubles
- Facts where a number is added to itself, like 7 + 7 = 14.
- near doubles
- Facts one away from a double, like 7 + 8, which is one more than 7 + 7.
- make a ten
- Filling up a ten first to add, like 8 + 5 = 8 + 2 + 3 = 13.
- fact family
- Related facts that use the same three numbers, like 6 + 9 = 15 and 15 − 9 = 6.
- related facts
- Adding and subtracting facts with the same numbers, like 8 + 5 = 13 and 13 − 5 = 8.
- equation
- A number sentence with an equal sign, like 9 + 4 = 13.
- unknown
- The missing number in a problem, often shown with a box or a question mark.
- sum
- The answer when you add numbers together.
- difference
- The answer when you subtract; it also tells how much more one amount is.
Ready to build your child’s confidence with facts within 20?
In Bobby's Math Club, your child practices these skills at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free.
Join the club
Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.
Which math standards does enVision Mathematics Grade 2 Topic 1 cover?
enVision Mathematics Grade 2 Topic 1 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.